[unreadable] We propose to develop a dual energy x-ray detector that will allow us to move towards an ideal digital radiography system for mammography. In our approach, we propose to implement a novel technology where the incoming x-ray photons are energy-separated. Compared to presently available dual energy radiography units, which use either filter-attenuated signals or consecutive high and low-energy exposures, our system will offer greater potential in detecting micro-calcifications as well as injected contrast agents without the disadvantages of present systems. It will also have high x-ray conversion efficiency, high limiting resolution, ultra-low noise, linear response and high dynamic range. A radiography system with such specifications offers the possibility not only of replacing x-ray films, but also improving image quality as well as providing opportunities for advanced breast imaging studies. It can also facilitate medical image management, computer-aided diagnosis and tele-mammography. [unreadable] [unreadable] Our approach consists of developing a high-resolution detector. The incoming x-rays are detected inside high spatial and energy resolution detectors. The signal is input into each channel of a custom designed readout integrated circuit (1C). Each signal is then amplified, integrated and recorded. The processed signal is processed and reconstructed into a two-dimensional image. Finally the image is displayed on a high resolution monitor. [unreadable] [unreadable] During Phase I, we will explore the feasibility of this novel concept mainly through computer simulations and discrete component testing of the critical circuits. At the end of Phase I the feasibility will be demonstrated and a preliminary design of proposed detector system will be ready. During Phase II we plan to design, fabricate and test a new custom 1C readout chip and incorporate it with a suitable detector. The new detector system's imaging capability and performance will be determined and characterized. We also plan to fabricate a small prototype detector arm to make larger area images to demonstrate the capability of the new dual energy detectors using mammography phantoms and excised tissue samples. During Phase III we will seek funding for clinical trials with our collaboration partners and demonstrate our prototype dual energy mammography system to potential Phase III commercialization partners. [unreadable] [unreadable] We expect that our system will achieve significant improvements in both sensitivity and specificity in the detection of breast cancer. We thus anticipate that it will reduce both false negative and false positive results in breast cancer screening and eventually lead to saving more lives and reducing unnecessary trauma to patients. [unreadable] [unreadable]